Charles Murray, the American ideologue and political scientist, made a career by holding the spectre of the "underclass" over the US. He found powerful allies in Britain, from Rupert Murdoch's Sunday Times, to New Labour's Gordon Brown.

There was never evidence to substantiate the existence of his heavily racialised group of disaffiliated poor people, who rejected society's values and represented a threat to social cohesion, the family and the Protestant work ethic. And despite the fact that the social breakdown he threatened never materialised, his conceptual legacy lives on – and gained further impetus after last year's riots when the spectre of damaging internal forces was again raised.

But perhaps the focus should be elsewhere. Last September, Lady [Ruth] Lister, the anti-poverty campaigner, referred to a "feral elite", challenging Kenneth Clarke's talk of an underclass "cut off from the mainstream in everything but its materialism".

We have now entered an age when it is the divisive and damaging effects of those who are very rich and powerful that we need to fear, rather than poor and powerless. This emerging "overclass" of fat cats and super rich seems to be profiting from current economic meltdown and political strictures about the public deficit, as the rest of us suffer.

This overclass, which has grown disproportionately powerful socially, politically and economically, seems to show little commitment to traditional social values. It shares many of the characteristics associated with Murray's notional underclass. It is tied in with some of the most damaging developments in our society: the extreme risk taking of the banking industry, unaccountable and overpowerful media proprietors, rising inequality and disadvantage, declining social mobility and a careless approach to vulnerable people. Key representatives of this amoral and isolated overclass are to be found among the leadership of tax avoiding corporations; unaccountable, asset stripping private equity companies; profiteers from the inordinately costly private finance initiative; corporate landlords imposing inflated rents funded by housing benefit; and outsourcing companies delivering poor value for money.

If concepts of social justice, democracy and equal opportunity still find popular favour, they are not embodied in this narrow but influential elite. As the workforce is rewarded with a declining proportion of GDP, reduced pensions and inadequate social care funding, so directors' pay has headed for the stratosphere and their taxes are cut. Even as this is justified in the name of private enterprise and competition, the money markets are undermining national economies, corporations are culling rather than creating jobs, and the fabric of communities, from high streets to higher education, is in jeopardy.

Perhaps most worrying is the overlap between this overclass and the government, separated from the rest of the population by education and wealth. It is a new and frightening kind of two nations that must now be contested.